Final answer:
Hybrid duplex and heteroduplex are both DNA structures involving pairing of complementary strands. Hybrid duplex forms during DNA replication, while heteroduplex forms during genetic recombination or repair.
Step-by-step explanation:
The relationship between hybrid duplex and heteroduplex is that they are both DNA structures that involve pairing of complementary strands. Hybrid duplex is a structure that occurs during DNA replication, where one strand of the newly synthesized DNA molecule is complimentary to the parental DNA strand, while the other strand is newly synthesized. Heteroduplex, on the other hand, is a structure that forms during genetic recombination or genetic repair, where two DNA strands with different sequences pair together.